struct dentry *wrapfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { struct dentry *ret, *parent; struct path lower_parent_path; int err = 0; BUG_ON(!nd); parent = dget_parent(dentry); wrapfs_get_lower_path(parent, &lower_parent_path); /* allocate dentry private data. We free it in ->d_release */ err = new_dentry_private_data(dentry); if (err) { ret = ERR_PTR(err); goto out; } ret = __wrapfs_lookup(dentry, nd->flags, &lower_parent_path); if (IS_ERR(ret)) goto out; if (ret) dentry = ret; if (dentry->d_inode) fsstack_copy_attr_times(dentry->d_inode, wrapfs_lower_inode(dentry->d_inode)); /* update parent directory's atime */ fsstack_copy_attr_atime(parent->d_inode, wrapfs_lower_inode(parent->d_inode)); out: wrapfs_put_lower_path(parent, &lower_parent_path); dput(parent); return ret; }
/* * On success: * fills dentry object appropriate values and returns NULL. * On fail (== error) * returns error ptr * * @dir : Parent inode. It is locked (dir->i_mutex) * @dentry : Target dentry to lookup. we should set each of fields. * (dentry->d_name is initialized already) * @nd : nameidata of parent inode */ struct dentry *sdcardfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { struct dentry *ret = NULL, *parent; struct path lower_parent_path; int err = 0; struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb); const struct cred *saved_cred = NULL; parent = dget_parent(dentry); if(!check_caller_access_to_name(parent->d_inode, dentry->d_name.name, sbi->options.derive, 0, 0)) { ret = ERR_PTR(-EACCES); printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n" " dentry: %s, task:%s\n", __func__, dentry->d_name.name, current->comm); goto out_err; } /* save current_cred and override it */ OVERRIDE_CRED_PTR(SDCARDFS_SB(dir->i_sb), saved_cred); sdcardfs_get_lower_path(parent, &lower_parent_path); /* allocate dentry private data. We free it in ->d_release */ err = new_dentry_private_data(dentry); if (err) { ret = ERR_PTR(err); goto out; } ret = __sdcardfs_lookup(dentry, flags, &lower_parent_path); if (IS_ERR(ret)) { goto out; } if (ret) dentry = ret; if (dentry->d_inode) { fsstack_copy_attr_times(dentry->d_inode, sdcardfs_lower_inode(dentry->d_inode)); /* get drived permission */ get_derived_permission(parent, dentry); fix_derived_permission(dentry->d_inode); } /* update parent directory's atime */ fsstack_copy_attr_atime(parent->d_inode, sdcardfs_lower_inode(parent->d_inode)); out: sdcardfs_put_lower_path(parent, &lower_parent_path); REVERT_CRED(saved_cred); out_err: dput(parent); return ret; }
/* * unionfs_lookup is the only special function which takes a dentry, yet we * do NOT want to call __unionfs_d_revalidate_chain because by definition, * we don't have a valid dentry here yet. */ static struct dentry *unionfs_lookup(struct inode *dir, struct dentry *dentry, /* XXX: pass flags to lower? */ unsigned int flags_unused) { struct dentry *ret, *parent; int err = 0; unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD); parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT); /* * As long as we lock/dget the parent, then can skip validating the * parent now; we may have to rebuild this dentry on the next * ->d_revalidate, however. */ /* allocate dentry private data. We free it in ->d_release */ err = new_dentry_private_data(dentry, UNIONFS_DMUTEX_CHILD); if (unlikely(err)) { ret = ERR_PTR(err); goto out; } ret = unionfs_lookup_full(dentry, parent, INTERPOSE_LOOKUP); if (!IS_ERR(ret)) { if (ret) dentry = ret; /* lookup_full can return multiple positive dentries */ if (dentry->d_inode && !S_ISDIR(dentry->d_inode->i_mode)) { BUG_ON(dbstart(dentry) < 0); unionfs_postcopyup_release(dentry); } unionfs_copy_attr_times(dentry->d_inode); } unionfs_check_inode(dir); if (!IS_ERR(ret)) unionfs_check_dentry(dentry); unionfs_check_dentry(parent); unionfs_unlock_dentry(dentry); /* locked in new_dentry_private data */ out: unionfs_unlock_parent(dentry, parent); unionfs_read_unlock(dentry->d_sb); return ret; }
/* * On success: * fills dentry object appropriate values and returns NULL. * On fail (== error) * returns error ptr * * @dir : Parent inode. It is locked (dir->i_mutex) * @dentry : Target dentry to lookup. we should set each of fields. * (dentry->d_name is initialized already) * @nd : nameidata of parent inode */ struct dentry *sdcardfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { struct dentry *ret, *parent; struct path lower_parent_path; int err = 0; OVERRIDE_CRED_PTR(SDCARDFS_SB(dir->i_sb)); parent = dget_parent(dentry); sdcardfs_get_lower_path(parent, &lower_parent_path); /* allocate dentry private data. We free it in ->d_release */ err = new_dentry_private_data(dentry); if (err) { ret = ERR_PTR(err); goto out; } ret = __sdcardfs_lookup(dentry, nd, &lower_parent_path); if (IS_ERR(ret)) { goto out; } if (ret) dentry = ret; if (dentry->d_inode) fsstack_copy_attr_times(dentry->d_inode, sdcardfs_lower_inode(dentry->d_inode)); /* update parent directory's atime */ fsstack_copy_attr_atime(parent->d_inode, sdcardfs_lower_inode(parent->d_inode)); out: sdcardfs_put_lower_path(parent, &lower_parent_path); dput(parent); REVERT_CRED(); return ret; }
struct dentry *amfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { int err; struct dentry *ret, *parent; struct path lower_parent_path; parent = dget_parent(dentry); amfs_get_lower_path(parent, &lower_parent_path); /* allocate dentry private data. We free it in ->d_release */ err = new_dentry_private_data(dentry); // printk("\n lookup.c-> dentry *amfs_lookup"); //aditi if (err) { ret = ERR_PTR(err); goto out; } ret = __amfs_lookup(dentry, flags, &lower_parent_path); if (IS_ERR(ret)) goto out; if (ret) dentry = ret; if (dentry->d_inode) fsstack_copy_attr_times(dentry->d_inode, amfs_lower_inode(dentry->d_inode)); /* update parent directory's atime */ fsstack_copy_attr_atime(parent->d_inode, amfs_lower_inode(parent->d_inode)); out: amfs_put_lower_path(parent, &lower_parent_path); dput(parent); return ret; }
/* * our custom d_alloc_root work-alike * * we can't use d_alloc_root if we want to use our own interpose function * unchanged, so we simply call our own "fake" d_alloc_root */ static struct dentry *sdcardfs_d_alloc_root(struct super_block *sb) { struct dentry *ret = NULL; if (sb) { static const struct qstr name = { .name = "/", .len = 1 }; ret = __d_alloc(sb, &name); if (ret) { d_set_d_op(ret, &sdcardfs_ci_dops); ret->d_parent = ret; } } return ret; } /* * There is no need to lock the sdcardfs_super_info's rwsem as there is no * way anyone can have a reference to the superblock at this point in time. */ static int sdcardfs_read_super(struct super_block *sb, const char *dev_name, void *raw_data, int silent) { int err = 0; int debug; struct super_block *lower_sb; struct path lower_path; struct sdcardfs_sb_info *sb_info; void *pkgl_id; printk(KERN_INFO "sdcardfs: version %s\n", SDCARDFS_VERSION); if (!dev_name) { printk(KERN_ERR "sdcardfs: read_super: missing dev_name argument\n"); err = -EINVAL; goto out; } printk(KERN_INFO "sdcardfs: dev_name -> %s\n", dev_name); printk(KERN_INFO "sdcardfs: options -> %s\n", (char *)raw_data); /* parse lower path */ err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &lower_path); if (err) { printk(KERN_ERR "sdcardfs: error accessing " "lower directory '%s'\n", dev_name); goto out; } /* allocate superblock private data */ sb->s_fs_info = kzalloc(sizeof(struct sdcardfs_sb_info), GFP_KERNEL); if (!SDCARDFS_SB(sb)) { printk(KERN_CRIT "sdcardfs: read_super: out of memory\n"); err = -ENOMEM; goto out_free; } sb_info = sb->s_fs_info; /* parse options */ err = parse_options(sb, raw_data, silent, &debug, &sb_info->options); if (err) { printk(KERN_ERR "sdcardfs: invalid options or out of memory\n"); goto out_freesbi; } pkgl_id = packagelist_create(); if(IS_ERR(pkgl_id)) goto out_freesbi; else sb_info->pkgl_id = pkgl_id; /* set the lower superblock field of upper superblock */ lower_sb = lower_path.dentry->d_sb; atomic_inc(&lower_sb->s_active); sdcardfs_set_lower_super(sb, lower_sb); /* inherit maxbytes from lower file system */ sb->s_maxbytes = lower_sb->s_maxbytes; /* * Our c/m/atime granularity is 1 ns because we may stack on file * systems whose granularity is as good. */ sb->s_time_gran = 1; sb->s_magic = SDCARDFS_SUPER_MAGIC; if (sb_info->options.type != TYPE_NONE) sb->s_op = &sdcardfs_multimount_sops; else sb->s_op = &sdcardfs_sops; /* see comment next to the definition of sdcardfs_d_alloc_root */ sb->s_root = sdcardfs_d_alloc_root(sb); if (!sb->s_root) { err = -ENOMEM; goto out_sput; } /* link the upper and lower dentries */ sb->s_root->d_fsdata = NULL; err = new_dentry_private_data(sb->s_root); if (err) goto out_freeroot; /* set the lower dentries for s_root */ sdcardfs_set_lower_path(sb->s_root, &lower_path); /* call interpose to create the upper level inode */ err = sdcardfs_interpose(sb->s_root, sb, &lower_path); if (!err) { /* setup permission policy */ if(sb_info->options.multi_user){ setup_derived_state(sb->s_root->d_inode, PERM_PRE_ROOT, sb_info->options.userid, AID_ROOT, sb_info->options.gid, false); sb_info->obbpath_s = kzalloc(PATH_MAX, GFP_KERNEL); snprintf(sb_info->obbpath_s, PATH_MAX, "%s/obb", dev_name); err = prepare_dir(sb_info->obbpath_s, sb_info->options.fs_low_uid, sb_info->options.fs_low_gid, 00775); } else { setup_derived_state(sb->s_root->d_inode, PERM_ROOT, sb_info->options.userid, AID_ROOT, sb_info->options.gid, false); sb_info->obbpath_s = kzalloc(PATH_MAX, GFP_KERNEL); snprintf(sb_info->obbpath_s, PATH_MAX, "%s/Android/obb", dev_name); } fix_derived_permission(sb->s_root->d_inode); sb_info->devpath = kzalloc(PATH_MAX, GFP_KERNEL); if(sb_info->devpath && dev_name) strncpy(sb_info->devpath, dev_name, strlen(dev_name)); if (!silent && !err) printk(KERN_INFO "sdcardfs: mounted on top of %s type %s\n", dev_name, lower_sb->s_type->name); goto out; } /* else error: fall through */ free_dentry_private_data(sb->s_root); out_freeroot: dput(sb->s_root); out_sput: /* drop refs we took earlier */ atomic_dec(&lower_sb->s_active); packagelist_destroy(sb_info->pkgl_id); out_freesbi: kfree(SDCARDFS_SB(sb)); sb->s_fs_info = NULL; out_free: path_put(&lower_path); out: return err; }
/* * There is no need to lock the wrapfs_super_info's rwsem as there is no * way anyone can have a reference to the superblock at this point in time. */ static int wrapfs_read_super(struct super_block *sb, void *raw_data, int silent) { int err = 0; struct super_block *lower_sb; struct path lower_path; char *dev_name = (char *) raw_data; struct inode *inode; if (!dev_name) { printk(KERN_ERR "wrapfs: read_super: missing dev_name argument\n"); err = -EINVAL; goto out; } /* parse lower path */ err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &lower_path); if (err) { printk(KERN_ERR "wrapfs: error accessing " "lower directory '%s'\n", dev_name); goto out; } /* allocate superblock private data */ sb->s_fs_info = kzalloc(sizeof(struct wrapfs_sb_info), GFP_KERNEL); if (!WRAPFS_SB(sb)) { printk(KERN_CRIT "wrapfs: read_super: out of memory\n"); err = -ENOMEM; goto out_free; } /* set the lower superblock field of upper superblock */ lower_sb = lower_path.dentry->d_sb; atomic_inc(&lower_sb->s_active); wrapfs_set_lower_super(sb, lower_sb); /* inherit maxbytes from lower file system */ sb->s_maxbytes = lower_sb->s_maxbytes; /* * Our c/m/atime granularity is 1 ns because we may stack on file * systems whose granularity is as good. */ sb->s_time_gran = 1; sb->s_op = &wrapfs_sops; /* get a new inode and allocate our root dentry */ inode = wrapfs_iget(sb, lower_path.dentry->d_inode); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_sput; } sb->s_root = d_alloc_root(inode); if (!sb->s_root) { err = -ENOMEM; goto out_iput; } d_set_d_op(sb->s_root, &wrapfs_dops); /* link the upper and lower dentries */ sb->s_root->d_fsdata = NULL; err = new_dentry_private_data(sb->s_root); if (err) goto out_freeroot; /* if get here: cannot have error */ /* set the lower dentries for s_root */ wrapfs_set_lower_path(sb->s_root, &lower_path); /* * No need to call interpose because we already have a positive * dentry, which was instantiated by d_alloc_root. Just need to * d_rehash it. */ d_rehash(sb->s_root); if (!silent) printk(KERN_INFO "wrapfs: mounted on top of %s type %s\n", dev_name, lower_sb->s_type->name); goto out; /* all is well */ /* no longer needed: free_dentry_private_data(sb->s_root); */ out_freeroot: dput(sb->s_root); out_iput: iput(inode); out_sput: /* drop refs we took earlier */ atomic_dec(&lower_sb->s_active); kfree(WRAPFS_SB(sb)); sb->s_fs_info = NULL; out_free: path_put(&lower_path); out: return err; }
struct dentry *unionfs_lookup_backend(struct dentry *dentry, struct nameidata *nd, int lookupmode) { int err = 0; struct dentry *hidden_dentry = NULL; struct dentry *wh_hidden_dentry = NULL; struct dentry *hidden_dir_dentry = NULL; struct dentry *parent_dentry = NULL; int bindex, bstart, bend, bopaque; int dentry_count = 0; /* Number of positive dentries. */ int first_dentry_offset = -1; struct dentry *first_hidden_dentry = NULL; struct vfsmount *first_hidden_mnt = NULL; int locked_parent = 0; int locked_child = 0; int opaque; char *whname = NULL; const char *name; int namelen; /* We should already have a lock on this dentry in the case of a * partial lookup, or a revalidation. Otherwise it is returned from * new_dentry_private_data already locked. */ if (lookupmode == INTERPOSE_PARTIAL || lookupmode == INTERPOSE_REVAL || lookupmode == INTERPOSE_REVAL_NEG) verify_locked(dentry); else { BUG_ON(UNIONFS_D(dentry) != NULL); locked_child = 1; } if (lookupmode != INTERPOSE_PARTIAL) if ((err = new_dentry_private_data(dentry))) goto out; /* must initialize dentry operations */ dentry->d_op = &unionfs_dops; parent_dentry = dget_parent(dentry); /* We never partial lookup the root directory. */ if (parent_dentry != dentry) { unionfs_lock_dentry(parent_dentry); locked_parent = 1; } else { dput(parent_dentry); parent_dentry = NULL; goto out; } name = dentry->d_name.name; namelen = dentry->d_name.len; /* No dentries should get created for possible whiteout names. */ if (!is_validname(name)) { err = -EPERM; goto out_free; } /* Now start the actual lookup procedure. */ bstart = dbstart(parent_dentry); bend = dbend(parent_dentry); bopaque = dbopaque(parent_dentry); BUG_ON(bstart < 0); /* It would be ideal if we could convert partial lookups to only have * to do this work when they really need to. It could probably improve * performance quite a bit, and maybe simplify the rest of the code. */ if (lookupmode == INTERPOSE_PARTIAL) { bstart++; if ((bopaque != -1) && (bopaque < bend)) bend = bopaque; } for (bindex = bstart; bindex <= bend; bindex++) { hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); if (lookupmode == INTERPOSE_PARTIAL && hidden_dentry) continue; BUG_ON(hidden_dentry != NULL); hidden_dir_dentry = unionfs_lower_dentry_idx(parent_dentry, bindex); /* if the parent hidden dentry does not exist skip this */ if (!(hidden_dir_dentry && hidden_dir_dentry->d_inode)) continue; /* also skip it if the parent isn't a directory. */ if (!S_ISDIR(hidden_dir_dentry->d_inode->i_mode)) continue; /* Reuse the whiteout name because its value doesn't change. */ if (!whname) { whname = alloc_whname(name, namelen); if (IS_ERR(whname)) { err = PTR_ERR(whname); goto out_free; } } /* check if whiteout exists in this branch: lookup .wh.foo */ wh_hidden_dentry = lookup_one_len(whname, hidden_dir_dentry, namelen + UNIONFS_WHLEN); if (IS_ERR(wh_hidden_dentry)) { dput(first_hidden_dentry); mntput(first_hidden_mnt); err = PTR_ERR(wh_hidden_dentry); goto out_free; } if (wh_hidden_dentry->d_inode) { /* We found a whiteout so lets give up. */ if (S_ISREG(wh_hidden_dentry->d_inode->i_mode)) { set_dbend(dentry, bindex); set_dbopaque(dentry, bindex); dput(wh_hidden_dentry); break; } err = -EIO; printk(KERN_NOTICE "EIO: Invalid whiteout entry type" " %d.\n", wh_hidden_dentry->d_inode->i_mode); dput(wh_hidden_dentry); dput(first_hidden_dentry); mntput(first_hidden_mnt); goto out_free; } dput(wh_hidden_dentry); wh_hidden_dentry = NULL; /* Now do regular lookup; lookup foo */ nd->dentry = unionfs_lower_dentry_idx(dentry, bindex); /* FIXME: fix following line for mount point crossing */ nd->mnt = unionfs_lower_mnt_idx(parent_dentry, bindex); hidden_dentry = lookup_one_len_nd(name, hidden_dir_dentry, namelen, nd); if (IS_ERR(hidden_dentry)) { dput(first_hidden_dentry); mntput(first_hidden_mnt); err = PTR_ERR(hidden_dentry); goto out_free; } /* Store the first negative dentry specially, because if they * are all negative we need this for future creates. */ if (!hidden_dentry->d_inode) { if (!first_hidden_dentry && (dbstart(dentry) == -1)) { first_hidden_dentry = hidden_dentry; /* FIXME: following line needs to be changed * to allow mountpoint crossing */ first_hidden_mnt = mntget( unionfs_lower_mnt_idx(parent_dentry, bindex)); first_dentry_offset = bindex; } else dput(hidden_dentry); continue; } /* number of positive dentries */ dentry_count++; /* store underlying dentry */ if (dbstart(dentry) == -1) set_dbstart(dentry, bindex); unionfs_set_lower_dentry_idx(dentry, bindex, hidden_dentry); /* FIXME: the following line needs to get fixed to allow * mountpoint crossing */ unionfs_set_lower_mnt_idx(dentry, bindex, mntget(unionfs_lower_mnt_idx(parent_dentry, bindex))); set_dbend(dentry, bindex); /* update parent directory's atime with the bindex */ fsstack_copy_attr_atime(parent_dentry->d_inode, hidden_dir_dentry->d_inode); /* We terminate file lookups here. */ if (!S_ISDIR(hidden_dentry->d_inode->i_mode)) { if (lookupmode == INTERPOSE_PARTIAL) continue; if (dentry_count == 1) goto out_positive; /* This can only happen with mixed D-*-F-* */ BUG_ON(!S_ISDIR(unionfs_lower_dentry(dentry)->d_inode->i_mode)); continue; } opaque = is_opaque_dir(dentry, bindex); if (opaque < 0) { dput(first_hidden_dentry); mntput(first_hidden_mnt); err = opaque; goto out_free; } else if (opaque) { set_dbend(dentry, bindex); set_dbopaque(dentry, bindex); break; } } if (dentry_count) goto out_positive; else goto out_negative; out_negative: if (lookupmode == INTERPOSE_PARTIAL) goto out; /* If we've only got negative dentries, then use the leftmost one. */ if (lookupmode == INTERPOSE_REVAL) { if (dentry->d_inode) UNIONFS_I(dentry->d_inode)->stale = 1; goto out; } /* This should only happen if we found a whiteout. */ if (first_dentry_offset == -1) { nd->dentry = dentry; /* FIXME: fix following line for mount point crossing */ nd->mnt = unionfs_lower_mnt_idx(parent_dentry, bindex); first_hidden_dentry = lookup_one_len_nd(name, hidden_dir_dentry, namelen, nd); first_dentry_offset = bindex; if (IS_ERR(first_hidden_dentry)) { err = PTR_ERR(first_hidden_dentry); goto out; } /* FIXME: the following line needs to be changed to allow * mountpoint crossing */ first_hidden_mnt = mntget(unionfs_lower_mnt_idx(dentry, bindex)); } unionfs_set_lower_dentry_idx(dentry, first_dentry_offset, first_hidden_dentry); unionfs_set_lower_mnt_idx(dentry, first_dentry_offset, first_hidden_mnt); set_dbstart(dentry, first_dentry_offset); set_dbend(dentry, first_dentry_offset); if (lookupmode == INTERPOSE_REVAL_NEG) BUG_ON(dentry->d_inode != NULL); else d_add(dentry, NULL); goto out; /* This part of the code is for positive dentries. */ out_positive: BUG_ON(dentry_count <= 0); /* If we're holding onto the first negative dentry & corresponding * vfsmount - throw it out. */ dput(first_hidden_dentry); mntput(first_hidden_mnt); /* Partial lookups need to reinterpose, or throw away older negs. */ if (lookupmode == INTERPOSE_PARTIAL) { if (dentry->d_inode) { unionfs_reinterpose(dentry); goto out; } /* This somehow turned positive, so it is as if we had a * negative revalidation. */ lookupmode = INTERPOSE_REVAL_NEG; update_bstart(dentry); bstart = dbstart(dentry); bend = dbend(dentry); } err = unionfs_interpose(dentry, dentry->d_sb, lookupmode); if (err) goto out_drop; goto out; out_drop: d_drop(dentry); out_free: /* should dput all the underlying dentries on error condition */ bstart = dbstart(dentry); if (bstart >= 0) { bend = dbend(dentry); for (bindex = bstart; bindex <= bend; bindex++) { dput(unionfs_lower_dentry_idx(dentry, bindex)); mntput(unionfs_lower_mnt_idx(dentry, bindex)); } } kfree(UNIONFS_D(dentry)->lower_paths); UNIONFS_D(dentry)->lower_paths = NULL; set_dbstart(dentry, -1); set_dbend(dentry, -1); out: if (!err && UNIONFS_D(dentry)) { BUG_ON(dbend(dentry) > UNIONFS_D(dentry)->bcount); BUG_ON(dbend(dentry) > sbmax(dentry->d_sb)); BUG_ON(dbstart(dentry) < 0); } kfree(whname); if (locked_parent) unionfs_unlock_dentry(parent_dentry); dput(parent_dentry); if (locked_child) unionfs_unlock_dentry(dentry); return ERR_PTR(err); }
/* * our custom d_alloc_root work-alike * * we can't use d_alloc_root if we want to use our own interpose function * unchanged, so we simply call our own "fake" d_alloc_root */ static struct dentry *unionfs_d_alloc_root(struct super_block *sb) { struct dentry *ret = NULL; if (sb) { static const struct qstr name = { .name = "/", .len = 1 }; ret = d_alloc(NULL, &name); if (likely(ret)) { ret->d_op = &unionfs_dops; ret->d_sb = sb; ret->d_parent = ret; } } return ret; } /* * There is no need to lock the unionfs_super_info's rwsem as there is no * way anyone can have a reference to the superblock at this point in time. */ static int unionfs_read_super(struct super_block *sb, void *raw_data, int silent) { int err = 0; struct unionfs_dentry_info *lower_root_info = NULL; int bindex, bstart, bend; if (!raw_data) { printk(KERN_ERR "unionfs: read_super: missing data argument\n"); err = -EINVAL; goto out; } /* Allocate superblock private data */ sb->s_fs_info = kzalloc(sizeof(struct unionfs_sb_info), GFP_KERNEL); if (unlikely(!UNIONFS_SB(sb))) { printk(KERN_CRIT "unionfs: read_super: out of memory\n"); err = -ENOMEM; goto out; } UNIONFS_SB(sb)->bend = -1; atomic_set(&UNIONFS_SB(sb)->generation, 1); init_rwsem(&UNIONFS_SB(sb)->rwsem); UNIONFS_SB(sb)->high_branch_id = -1; /* -1 == invalid branch ID */ lower_root_info = unionfs_parse_options(sb, raw_data); if (IS_ERR(lower_root_info)) { printk(KERN_ERR "unionfs: read_super: error while parsing options " "(err = %ld)\n", PTR_ERR(lower_root_info)); err = PTR_ERR(lower_root_info); lower_root_info = NULL; goto out_free; } if (lower_root_info->bstart == -1) { err = -ENOENT; goto out_free; } /* set the lower superblock field of upper superblock */ bstart = lower_root_info->bstart; BUG_ON(bstart != 0); sbend(sb) = bend = lower_root_info->bend; for (bindex = bstart; bindex <= bend; bindex++) { struct dentry *d = lower_root_info->lower_paths[bindex].dentry; atomic_inc(&d->d_sb->s_active); unionfs_set_lower_super_idx(sb, bindex, d->d_sb); } /* max Bytes is the maximum bytes from highest priority branch */ sb->s_maxbytes = unionfs_lower_super_idx(sb, 0)->s_maxbytes; /* * Our c/m/atime granularity is 1 ns because we may stack on file * systems whose granularity is as good. This is important for our * time-based cache coherency. */ sb->s_time_gran = 1; sb->s_op = &unionfs_sops; /* See comment next to the definition of unionfs_d_alloc_root */ sb->s_root = unionfs_d_alloc_root(sb); if (unlikely(!sb->s_root)) { err = -ENOMEM; goto out_dput; } /* link the upper and lower dentries */ sb->s_root->d_fsdata = NULL; err = new_dentry_private_data(sb->s_root, UNIONFS_DMUTEX_ROOT); if (unlikely(err)) goto out_freedpd; /* Set the lower dentries for s_root */ for (bindex = bstart; bindex <= bend; bindex++) { struct dentry *d; struct vfsmount *m; d = lower_root_info->lower_paths[bindex].dentry; m = lower_root_info->lower_paths[bindex].mnt; unionfs_set_lower_dentry_idx(sb->s_root, bindex, d); unionfs_set_lower_mnt_idx(sb->s_root, bindex, m); } dbstart(sb->s_root) = bstart; dbend(sb->s_root) = bend; /* Set the generation number to one, since this is for the mount. */ atomic_set(&UNIONFS_D(sb->s_root)->generation, 1); /* * Call interpose to create the upper level inode. Only * INTERPOSE_LOOKUP can return a value other than 0 on err. */ err = PTR_ERR(unionfs_interpose(sb->s_root, sb, 0)); unionfs_unlock_dentry(sb->s_root); if (!err) goto out; /* else fall through */ out_freedpd: if (UNIONFS_D(sb->s_root)) { kfree(UNIONFS_D(sb->s_root)->lower_paths); free_dentry_private_data(sb->s_root); } dput(sb->s_root); out_dput: if (lower_root_info && !IS_ERR(lower_root_info)) { for (bindex = lower_root_info->bstart; bindex <= lower_root_info->bend; bindex++) { struct dentry *d; struct vfsmount *m; d = lower_root_info->lower_paths[bindex].dentry; m = lower_root_info->lower_paths[bindex].mnt; dput(d); /* initializing: can't use unionfs_mntput here */ mntput(m); /* drop refs we took earlier */ atomic_dec(&d->d_sb->s_active); } kfree(lower_root_info->lower_paths); kfree(lower_root_info); lower_root_info = NULL; } out_free: kfree(UNIONFS_SB(sb)->data); kfree(UNIONFS_SB(sb)); sb->s_fs_info = NULL; out: if (lower_root_info && !IS_ERR(lower_root_info)) { kfree(lower_root_info->lower_paths); kfree(lower_root_info); } return err; }
/* * There is no need to lock the wrapfs_super_info's rwsem as there is no * way anyone can have a reference to the superblock at this point in time. */ static int wrapfs_read_super(struct super_block *sb, void *raw_data, int silent) { int err = 0, i = 0; struct wrapfs_dentry_info *lower_root_info = NULL; struct inode *inode = NULL; if (!raw_data) { printk(KERN_ERR "u2fs: read_super: missing data argument\n"); err = -EINVAL; goto out; } /* allocate superblock private data */ sb->s_fs_info = kzalloc(sizeof(struct wrapfs_sb_info), GFP_KERNEL); if (!WRAPFS_SB(sb)) { printk(KERN_CRIT "u2fs: read_super: out of memory\n"); err = -ENOMEM; goto out_free; } atomic_set(&WRAPFS_SB(sb)->generation, 1); WRAPFS_SB(sb)->high_branch_id = -1; /* Parsing the Inputs */ lower_root_info = wrapfs_parse_options(sb, raw_data); if (IS_ERR(lower_root_info)) { printk(KERN_ERR "u2fs: read_super: error while parsing options" "(err = %ld)\n", PTR_ERR(lower_root_info)); err = PTR_ERR(lower_root_info); lower_root_info = NULL; goto out_free; } /* set the lower superblock field of upper superblock */ for (i = 0; i <= 1; i++) { struct dentry *d = lower_root_info->lower_paths[i].dentry; atomic_inc(&d->d_sb->s_active); wrapfs_set_lower_super_idx(sb, i, d->d_sb); } /* inherit maxbytes from highest priority branch */ sb->s_maxbytes = wrapfs_lower_super_idx(sb, 0)->s_maxbytes; /* * Our c/m/atime granularity is 1 ns because we may stack on file * systems whose granularity is as good. */ sb->s_time_gran = 1; sb->s_op = &wrapfs_sops; /* get a new inode and allocate our root dentry */ inode = wrapfs_new_iget(sb, iunique(sb, 1)); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_sput; } sb->s_root = d_alloc_root(inode); if (unlikely(!sb->s_root)) { err = -ENOMEM; goto out_iput; } d_set_d_op(sb->s_root, &wrapfs_dops); /* link the upper and lower dentries */ sb->s_root->d_fsdata = NULL; err = new_dentry_private_data(sb->s_root); if (unlikely(err)) goto out_freeroot; /* if get here: cannot have error */ /* set the lower dentries for s_root */ for (i = 0; i <= 1 ; i++) { struct dentry *d; struct vfsmount *m; d = lower_root_info->lower_paths[i].dentry; m = lower_root_info->lower_paths[i].mnt; wrapfs_set_lower_dentry_idx(sb->s_root, i, d); wrapfs_set_lower_mnt_idx(sb->s_root, i, m); } atomic_set(&WRAPFS_D(sb->s_root)->generation, 1); if (atomic_read(&inode->i_count) <= 1) wrapfs_fill_inode(sb->s_root, inode); /* * No need to call interpose because we already have a positive * dentry, which was instantiated by d_alloc_root. Just need to * d_rehash it. */ d_rehash(sb->s_root); if (!silent) printk(KERN_INFO "u2fs: mounted on top of type\n"); goto out; /* all is well */ /* no longer needed: free_dentry_private_data(sb->s_root); */ out_freeroot: if (WRAPFS_D(sb->s_root)) { kfree(WRAPFS_D(sb->s_root)->lower_paths); free_dentry_private_data(sb->s_root); } dput(sb->s_root); out_iput: iput(inode); out_sput: /* drop refs we took earlier */ if (lower_root_info && !IS_ERR(lower_root_info)) { for (i = 0; i <= 1; i++) { struct dentry *d; d = lower_root_info->lower_paths[i].dentry; atomic_dec(&d->d_sb->s_active); path_put(&lower_root_info->lower_paths[i]); } kfree(lower_root_info->lower_paths); kfree(lower_root_info); lower_root_info = NULL; } out_free: kfree(WRAPFS_SB(sb)->data); kfree(WRAPFS_SB(sb)); sb->s_fs_info = NULL; out: if (lower_root_info && !IS_ERR(lower_root_info)) { kfree(lower_root_info->lower_paths); kfree(lower_root_info); } return err; }
struct dentry *unionfs_lookup_backend(struct dentry *dentry, int lookupmode) { int err = 0; struct dentry *hidden_dentry = NULL; struct dentry *wh_hidden_dentry = NULL; struct dentry *hidden_dir_dentry = NULL; struct dentry *parent_dentry = NULL; int bindex, bstart, bend, bopaque; int dentry_count = 0; /* Number of positive dentries. */ int first_dentry_offset = -1; struct dentry *first_hidden_dentry = NULL; int locked_parent = 0; int locked_child = 0; int opaque; char *whname = NULL; const char *name; int namelen; print_entry("mode = %d", lookupmode); /* We should already have a lock on this dentry in the case of a * partial lookup, or a revalidation. Otherwise it is returned from * new_dentry_private_data already locked. */ if (lookupmode == INTERPOSE_PARTIAL || lookupmode == INTERPOSE_REVAL || lookupmode == INTERPOSE_REVAL_NEG) { verify_locked(dentry); } else { BUG_ON(dtopd_nocheck(dentry) != NULL); locked_child = 1; } if (lookupmode != INTERPOSE_PARTIAL) if ((err = new_dentry_private_data(dentry))) goto out; /* must initialize dentry operations */ dentry->d_op = &unionfs_dops; parent_dentry = GET_PARENT(dentry); /* We never partial lookup the root directory. */ if (parent_dentry != dentry) { lock_dentry(parent_dentry); locked_parent = 1; } else { DPUT(parent_dentry); parent_dentry = NULL; goto out; } fist_print_dentry("IN unionfs_lookup (parent)", parent_dentry); fist_print_dentry("IN unionfs_lookup (child)", dentry); name = dentry->d_name.name; namelen = dentry->d_name.len; /* No dentries should get created for possible whiteout names. */ if (!is_validname(name)) { err = -EPERM; goto out_free; } /* Now start the actual lookup procedure. */ bstart = dbstart(parent_dentry); bend = dbend(parent_dentry); bopaque = dbopaque(parent_dentry); BUG_ON(bstart < 0); /* It would be ideal if we could convert partial lookups to only have * to do this work when they really need to. It could probably improve * performance quite a bit, and maybe simplify the rest of the code. */ if (lookupmode == INTERPOSE_PARTIAL) { bstart++; if ((bopaque != -1) && (bopaque < bend)) bend = bopaque; } fist_dprint(8, "bstart = %d, bend = %d\n", bstart, bend); for (bindex = bstart; bindex <= bend; bindex++) { hidden_dentry = dtohd_index(dentry, bindex); if (lookupmode == INTERPOSE_PARTIAL && hidden_dentry) continue; BUG_ON(hidden_dentry != NULL); hidden_dir_dentry = dtohd_index(parent_dentry, bindex); /* if the parent hidden dentry does not exist skip this */ if (!(hidden_dir_dentry && hidden_dir_dentry->d_inode)) continue; /* also skip it if the parent isn't a directory. */ if (!S_ISDIR(hidden_dir_dentry->d_inode->i_mode)) continue; /* Reuse the whiteout name because its value doesn't change. */ if (!whname) { whname = alloc_whname(name, namelen); if (IS_ERR(whname)) { err = PTR_ERR(whname); goto out_free; } } /* check if whiteout exists in this branch: lookup .wh.foo */ wh_hidden_dentry = LOOKUP_ONE_LEN(whname, hidden_dir_dentry, namelen + WHLEN); if (IS_ERR(wh_hidden_dentry)) { DPUT(first_hidden_dentry); err = PTR_ERR(wh_hidden_dentry); goto out_free; } if (wh_hidden_dentry->d_inode) { /* We found a whiteout so lets give up. */ fist_dprint(8, "whiteout found in %d\n", bindex); if (S_ISREG(wh_hidden_dentry->d_inode->i_mode)) { set_dbend(dentry, bindex); set_dbopaque(dentry, bindex); DPUT(wh_hidden_dentry); break; } err = -EIO; printk(KERN_NOTICE "EIO: Invalid whiteout entry type" " %d.\n", wh_hidden_dentry->d_inode->i_mode); DPUT(wh_hidden_dentry); DPUT(first_hidden_dentry); goto out_free; } DPUT(wh_hidden_dentry); wh_hidden_dentry = NULL; /* Now do regular lookup; lookup foo */ hidden_dentry = LOOKUP_ONE_LEN(name, hidden_dir_dentry, namelen); fist_print_generic_dentry("hidden result", hidden_dentry); if (IS_ERR(hidden_dentry)) { DPUT(first_hidden_dentry); err = PTR_ERR(hidden_dentry); goto out_free; } /* Store the first negative dentry specially, because if they * are all negative we need this for future creates. */ if (!hidden_dentry->d_inode) { if (!first_hidden_dentry && (dbstart(dentry) == -1)) { first_hidden_dentry = hidden_dentry; first_dentry_offset = bindex; } else { DPUT(hidden_dentry); } continue; } /* number of positive dentries */ dentry_count++; /* store underlying dentry */ if (dbstart(dentry) == -1) set_dbstart(dentry, bindex); set_dtohd_index(dentry, bindex, hidden_dentry); set_dbend(dentry, bindex); /* update parent directory's atime with the bindex */ fist_copy_attr_atime(parent_dentry->d_inode, hidden_dir_dentry->d_inode); /* We terminate file lookups here. */ if (!S_ISDIR(hidden_dentry->d_inode->i_mode)) { if (lookupmode == INTERPOSE_PARTIAL) continue; if (dentry_count == 1) goto out_positive; /* This can only happen with mixed D-*-F-* */ BUG_ON(!S_ISDIR(dtohd(dentry)->d_inode->i_mode)); continue; } opaque = is_opaque_dir(dentry, bindex); if (opaque < 0) { DPUT(first_hidden_dentry); err = opaque; goto out_free; } if (opaque) { set_dbend(dentry, bindex); set_dbopaque(dentry, bindex); break; } } if (dentry_count) goto out_positive; else goto out_negative; out_negative: if (lookupmode == INTERPOSE_PARTIAL) goto out; /* If we've only got negative dentries, then use the leftmost one. */ if (lookupmode == INTERPOSE_REVAL) { if (dentry->d_inode) { itopd(dentry->d_inode)->uii_stale = 1; } goto out; } /* This should only happen if we found a whiteout. */ if (first_dentry_offset == -1) { first_hidden_dentry = LOOKUP_ONE_LEN(name, hidden_dir_dentry, namelen); first_dentry_offset = bindex; if (IS_ERR(first_hidden_dentry)) { err = PTR_ERR(first_hidden_dentry); goto out; } } set_dtohd_index(dentry, first_dentry_offset, first_hidden_dentry); set_dbstart(dentry, first_dentry_offset); set_dbend(dentry, first_dentry_offset); if (lookupmode == INTERPOSE_REVAL_NEG) BUG_ON(dentry->d_inode != NULL); else d_add(dentry, NULL); goto out; /* This part of the code is for positive dentries. */ out_positive: BUG_ON(dentry_count <= 0); /* If we're holding onto the first negative dentry throw it out. */ DPUT(first_hidden_dentry); /* Partial lookups need to reinterpose, or throw away older negs. */ if (lookupmode == INTERPOSE_PARTIAL) { if (dentry->d_inode) { unionfs_reinterpose(dentry); goto out; } /* This somehow turned positive, so it is as if we had a * negative revalidation. */ lookupmode = INTERPOSE_REVAL_NEG; update_bstart(dentry); bstart = dbstart(dentry); bend = dbend(dentry); } err = unionfs_interpose(dentry, dentry->d_sb, lookupmode); if (err) goto out_drop; fist_checkinode(dentry->d_inode, "unionfs_lookup OUT: child"); fist_checkinode(parent_dentry->d_inode, "unionfs_lookup OUT: dir"); goto out; out_drop: d_drop(dentry); out_free: /* should dput all the underlying dentries on error condition */ bstart = dbstart(dentry); if (bstart >= 0) { bend = dbend(dentry); for (bindex = bstart; bindex <= bend; bindex++) DPUT(dtohd_index(dentry, bindex)); } KFREE(dtohd_ptr(dentry)); dtohd_ptr(dentry) = NULL; set_dbstart(dentry, -1); set_dbend(dentry, -1); out: if (!err && dtopd(dentry)) { BUG_ON(dbend(dentry) > dtopd(dentry)->udi_bcount); BUG_ON(dbend(dentry) > sbmax(dentry->d_sb)); BUG_ON(dbstart(dentry) < 0); } KFREE(whname); fist_print_dentry("OUT unionfs_lookup (parent)", parent_dentry); fist_print_dentry("OUT unionfs_lookup (child)", dentry); if (locked_parent) unlock_dentry(parent_dentry); DPUT(parent_dentry); if (locked_child) unlock_dentry(dentry); print_exit_status(err); return ERR_PTR(err); }
/* * our custom d_alloc_root work-alike * * we can't use d_alloc_root if we want to use our own interpose function * unchanged, so we simply call our own "fake" d_alloc_root */ static struct dentry *sdcardfs_d_alloc_root(struct super_block *sb) { struct dentry *ret = NULL; if (sb) { static const struct qstr name = { .name = "/", .len = 1 }; ret = d_alloc(NULL, &name); if (ret) { d_set_d_op(ret, &sdcardfs_dops); ret->d_sb = sb; ret->d_parent = ret; } } return ret; } /* * There is no need to lock the sdcardfs_super_info's rwsem as there is no * way anyone can have a reference to the superblock at this point in time. */ static int sdcardfs_read_super(struct super_block *sb, const char *dev_name, void *raw_data, int silent) { int err = 0; int debug; struct super_block *lower_sb; struct path lower_path; struct sdcardfs_sb_info *sb_info; if (!dev_name) { printk(KERN_ERR "sdcardfs: read_super: missing dev_name argument\n"); err = -EINVAL; goto out; } printk(KERN_INFO "sdcardfs: dev_name -> %s\n", dev_name); printk(KERN_INFO "sdcardfs: options -> %s\n", (char *)raw_data); /* parse lower path */ err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &lower_path); if (err) { printk(KERN_ERR "sdcardfs: error accessing " "lower directory '%s'\n", dev_name); goto out; } /* allocate superblock private data */ sb->s_fs_info = kzalloc(sizeof(struct sdcardfs_sb_info), GFP_KERNEL); if (!SDCARDFS_SB(sb)) { printk(KERN_CRIT "sdcardfs: read_super: out of memory\n"); err = -ENOMEM; goto out_free; } /* setup fs_uid and fs_gid for FAT emulation : wjlee */ sb_info = sb->s_fs_info; sb_info->fs_uid = AID_ROOT; sb_info->fs_gid = AID_SDCARD_RW; /* parse options */ err = parse_options(sb, raw_data, silent, &debug, &sb_info->options); if (err) { printk(KERN_ERR "sdcardfs: invalid options\n"); goto out_freesbi; } /* set the lower superblock field of upper superblock */ lower_sb = lower_path.dentry->d_sb; atomic_inc(&lower_sb->s_active); sdcardfs_set_lower_super(sb, lower_sb); /* inherit maxbytes from lower file system */ sb->s_maxbytes = lower_sb->s_maxbytes; /* * Our c/m/atime granularity is 1 ns because we may stack on file * systems whose granularity is as good. */ sb->s_time_gran = 1; sb->s_op = &sdcardfs_sops; /* see comment next to the definition of sdcardfs_d_alloc_root */ sb->s_root = sdcardfs_d_alloc_root(sb); if (!sb->s_root) { err = -ENOMEM; goto out_sput; } /* link the upper and lower dentries */ sb->s_root->d_fsdata = NULL; err = new_dentry_private_data(sb->s_root); if (err) goto out_freeroot; /* set the lower dentries for s_root */ sdcardfs_set_lower_path(sb->s_root, &lower_path); /* call interpose to create the upper level inode */ err = sdcardfs_interpose(sb->s_root, sb, &lower_path); if (!err) { if (!silent) printk(KERN_INFO "sdcardfs: mounted on top of %s type %s\n", dev_name, lower_sb->s_type->name); goto out; } /* else error: fall through */ free_dentry_private_data(sb->s_root); out_freeroot: dput(sb->s_root); out_sput: /* drop refs we took earlier */ atomic_dec(&lower_sb->s_active); out_freesbi: kfree(SDCARDFS_SB(sb)); sb->s_fs_info = NULL; out_free: path_put(&lower_path); out: return err; }
/* * There is no need to lock the unionfs_super_info's rwsem as there is no * way anyone can have a reference to the superblock at this point in time. */ static int unionfs_read_super(struct super_block *sb, void *raw_data, int silent) { int err = 0; struct unionfs_dentry_info *lower_root_info = NULL; int bindex, bstart, bend; struct inode *inode = NULL; if (!raw_data) { printk(KERN_ERR "unionfs: read_super: missing data argument\n"); err = -EINVAL; goto out; } /* Allocate superblock private data */ sb->s_fs_info = kzalloc(sizeof(struct unionfs_sb_info), GFP_KERNEL); if (unlikely(!UNIONFS_SB(sb))) { printk(KERN_CRIT "unionfs: read_super: out of memory\n"); err = -ENOMEM; goto out; } UNIONFS_SB(sb)->bend = -1; atomic_set(&UNIONFS_SB(sb)->generation, 1); init_rwsem(&UNIONFS_SB(sb)->rwsem); UNIONFS_SB(sb)->high_branch_id = -1; /* -1 == invalid branch ID */ lower_root_info = unionfs_parse_options(sb, raw_data); if (IS_ERR(lower_root_info)) { printk(KERN_ERR "unionfs: read_super: error while parsing options " "(err = %ld)\n", PTR_ERR(lower_root_info)); err = PTR_ERR(lower_root_info); lower_root_info = NULL; goto out_free; } if (lower_root_info->bstart == -1) { err = -ENOENT; goto out_free; } /* set the lower superblock field of upper superblock */ bstart = lower_root_info->bstart; BUG_ON(bstart != 0); sbend(sb) = bend = lower_root_info->bend; for (bindex = bstart; bindex <= bend; bindex++) { struct dentry *d = lower_root_info->lower_paths[bindex].dentry; atomic_inc(&d->d_sb->s_active); unionfs_set_lower_super_idx(sb, bindex, d->d_sb); } /* max Bytes is the maximum bytes from highest priority branch */ sb->s_maxbytes = unionfs_lower_super_idx(sb, 0)->s_maxbytes; /* * Our c/m/atime granularity is 1 ns because we may stack on file * systems whose granularity is as good. This is important for our * time-based cache coherency. */ sb->s_time_gran = 1; sb->s_op = &unionfs_sops; /* get a new inode and allocate our root dentry */ inode = unionfs_iget(sb, iunique(sb, UNIONFS_ROOT_INO)); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_dput; } sb->s_root = d_make_root(inode); if (unlikely(!sb->s_root)) { err = -ENOMEM; goto out_iput; } d_set_d_op(sb->s_root, &unionfs_dops); /* link the upper and lower dentries */ sb->s_root->d_fsdata = NULL; err = new_dentry_private_data(sb->s_root, UNIONFS_DMUTEX_ROOT); if (unlikely(err)) goto out_freedpd; /* if get here: cannot have error */ /* Set the lower dentries for s_root */ for (bindex = bstart; bindex <= bend; bindex++) { struct dentry *d; struct vfsmount *m; d = lower_root_info->lower_paths[bindex].dentry; m = lower_root_info->lower_paths[bindex].mnt; unionfs_set_lower_dentry_idx(sb->s_root, bindex, d); unionfs_set_lower_mnt_idx(sb->s_root, bindex, m); } dbstart(sb->s_root) = bstart; dbend(sb->s_root) = bend; /* Set the generation number to one, since this is for the mount. */ atomic_set(&UNIONFS_D(sb->s_root)->generation, 1); if (atomic_read(&inode->i_count) <= 1) unionfs_fill_inode(sb->s_root, inode); /* * No need to call interpose because we already have a positive * dentry, which was instantiated by d_alloc_root. Just need to * d_rehash it. */ d_rehash(sb->s_root); unionfs_unlock_dentry(sb->s_root); goto out; /* all is well */ out_freedpd: if (UNIONFS_D(sb->s_root)) { kfree(UNIONFS_D(sb->s_root)->lower_paths); free_dentry_private_data(sb->s_root); } dput(sb->s_root); out_iput: iput(inode); out_dput: if (lower_root_info && !IS_ERR(lower_root_info)) { for (bindex = lower_root_info->bstart; bindex <= lower_root_info->bend; bindex++) { struct dentry *d; d = lower_root_info->lower_paths[bindex].dentry; /* drop refs we took earlier */ atomic_dec(&d->d_sb->s_active); path_put(&lower_root_info->lower_paths[bindex]); } kfree(lower_root_info->lower_paths); kfree(lower_root_info); lower_root_info = NULL; } out_free: kfree(UNIONFS_SB(sb)->data); kfree(UNIONFS_SB(sb)); sb->s_fs_info = NULL; out: if (lower_root_info && !IS_ERR(lower_root_info)) { kfree(lower_root_info->lower_paths); kfree(lower_root_info); } return err; }
/* * There is no need to lock the esdfs_super_info's rwsem as there is no * way anyone can have a reference to the superblock at this point in time. */ static int esdfs_read_super(struct super_block *sb, const char *dev_name, void *raw_data, int silent) { int err = 0; struct super_block *lower_sb; struct path lower_path; struct esdfs_sb_info *sbi; struct inode *inode; if (!dev_name) { esdfs_msg(sb, KERN_ERR, "missing dev_name argument\n"); err = -EINVAL; goto out; } /* parse lower path */ err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &lower_path); if (err) { esdfs_msg(sb, KERN_ERR, "error accessing lower directory '%s'\n", dev_name); goto out; } /* allocate superblock private data */ sb->s_fs_info = kzalloc(sizeof(struct esdfs_sb_info), GFP_KERNEL); sbi = ESDFS_SB(sb); if (!sbi) { esdfs_msg(sb, KERN_CRIT, "read_super: out of memory\n"); err = -ENOMEM; goto out_pput; } /* set defaults and then parse the mount options */ memcpy(&sbi->lower_perms, &esdfs_perms_table[ESDFS_PERMS_LOWER_DEFAULT], sizeof(struct esdfs_perms)); memcpy(&sbi->upper_perms, &esdfs_perms_table[ESDFS_PERMS_UPPER_LEGACY], sizeof(struct esdfs_perms)); err = parse_options(sb, (char *)raw_data); if (err) goto out_free; /* set the lower superblock field of upper superblock */ lower_sb = lower_path.dentry->d_sb; atomic_inc(&lower_sb->s_active); esdfs_set_lower_super(sb, lower_sb); /* inherit maxbytes from lower file system */ sb->s_maxbytes = lower_sb->s_maxbytes; /* * Our c/m/atime granularity is 1 ns because we may stack on file * systems whose granularity is as good. */ sb->s_time_gran = 1; sb->s_op = &esdfs_sops; /* get a new inode and allocate our root dentry */ inode = esdfs_iget(sb, lower_path.dentry->d_inode); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_sput; } sb->s_root = d_make_root(inode); if (!sb->s_root) { err = -ENOMEM; goto out_iput; } d_set_d_op(sb->s_root, &esdfs_dops); /* link the upper and lower dentries */ sb->s_root->d_fsdata = NULL; err = new_dentry_private_data(sb->s_root); if (err) goto out_freeroot; /* if get here: cannot have error */ /* set the lower dentries for s_root */ esdfs_set_lower_path(sb->s_root, &lower_path); #ifdef CONFIG_SECURITY_SELINUX security_secctx_to_secid(ESDFS_LOWER_SECCTX, strlen(ESDFS_LOWER_SECCTX), &sbi->lower_secid); #endif /* * No need to call interpose because we already have a positive * dentry, which was instantiated by d_make_root. Just need to * d_rehash it. */ d_rehash(sb->s_root); if (!silent) esdfs_msg(sb, KERN_INFO, "mounted on top of %s type %s\n", dev_name, lower_sb->s_type->name); if (!ESDFS_DERIVE_PERMS(sbi)) goto out; /* let user know that we ignore this option in derived mode */ if (memcmp(&sbi->upper_perms, &esdfs_perms_table[ESDFS_PERMS_UPPER_LEGACY], sizeof(struct esdfs_perms))) esdfs_msg(sb, KERN_WARNING, "'upper' mount option ignored in derived mode\n"); /* all derived modes start with the same, basic root */ memcpy(&sbi->upper_perms, &esdfs_perms_table[ESDFS_PERMS_UPPER_DERIVED], sizeof(struct esdfs_perms)); /* * In Android 3.0 all user conent in the emulated storage tree was * stored in /data/media. Android 4.2 introduced multi-user support, * which required that the primary user's content be migrated from * /data/media to /data/media/0. The framework then uses bind mounts * to create per-process namespaces to isolate each user's tree at * /data/media/N. This approach of having each user in a common root * is now considered "legacy" by the sdcard service. */ if (test_opt(sbi, DERIVE_LEGACY)) { ESDFS_I(inode)->tree = ESDFS_TREE_ROOT_LEGACY; sbi->obb_parent = dget(sb->s_root); /* * Android 4.4 reorganized this sturcture yet again, so that the * primary user's content was again at the root. Secondary users' * content is found in Android/user/N. Emulated internal storage still * seems to use the legacy tree, but secondary external storage uses * this method. */ } else if (test_opt(sbi, DERIVE_UNIFIED)) ESDFS_I(inode)->tree = ESDFS_TREE_ROOT; /* * Later versions of Android organize user content using quantum * entanglement, which has a low probability of being supported by * this driver. */ else esdfs_msg(sb, KERN_WARNING, "unsupported derived permissions mode\n"); /* initialize root inode */ esdfs_derive_perms(sb->s_root); goto out; out_freeroot: dput(sb->s_root); out_iput: iput(inode); out_sput: /* drop refs we took earlier */ atomic_dec(&lower_sb->s_active); out_free: kfree(ESDFS_SB(sb)); sb->s_fs_info = NULL; out_pput: path_put(&lower_path); out: return err; }
/* * our custom d_alloc_root work-alike * * we can't use d_alloc_root if we want to use our own interpose function * unchanged, so we simply call our own "fake" d_alloc_root */ static struct dentry *sdcardfs_d_alloc_root(struct super_block *sb) { struct dentry *ret = NULL; //struct sdcardfs_sb_info *sbi = SDCARDFS_SB(sb); struct dentry *(*__d_alloc_new)(struct super_block *, const struct qstr *) = (void *)kallsyms_lookup_name("__d_alloc"); if (sb) { static const struct qstr name = { .name = "/", .len = 1 }; ret = __d_alloc_new(sb, &name); if (ret) { d_set_d_op(ret, &sdcardfs_ci_dops); ret->d_parent = ret; } } return ret; } /* * There is no need to lock the sdcardfs_super_info's rwsem as there is no * way anyone can have a reference to the superblock at this point in time. */ static int sdcardfs_read_super(struct super_block *sb, const char *dev_name, void *raw_data, int silent) { int err = 0; int debug; struct super_block *lower_sb; struct path lower_path; struct sdcardfs_sb_info *sb_info; void *pkgl_id; printk(KERN_INFO "sdcardfs version 2.0\n"); if (!dev_name) { printk(KERN_ERR "sdcardfs: read_super: missing dev_name argument\n"); err = -EINVAL; goto out; } printk(KERN_INFO "sdcardfs: dev_name -> %s\n", dev_name); printk(KERN_INFO "sdcardfs: options -> %s\n", (char *)raw_data); /* parse lower path */ err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &lower_path); if (err) { printk(KERN_ERR "sdcardfs: error accessing " "lower directory '%s'\n", dev_name); goto out; } /* allocate superblock private data */ sb->s_fs_info = kzalloc(sizeof(struct sdcardfs_sb_info), GFP_KERNEL); if (!SDCARDFS_SB(sb)) { printk(KERN_CRIT "sdcardfs: read_super: out of memory\n"); err = -ENOMEM; goto out_free; } sb_info = sb->s_fs_info; /* parse options */ err = parse_options(sb, raw_data, silent, &debug, &sb_info->options); if (err) { printk(KERN_ERR "sdcardfs: invalid options\n"); goto out_freesbi; } if (sb_info->options.derive != DERIVE_NONE) { pkgl_id = packagelist_create(sb_info->options.write_gid); if(IS_ERR(pkgl_id)) goto out_freesbi; else sb_info->pkgl_id = pkgl_id; } /* set the lower superblock field of upper superblock */ lower_sb = lower_path.dentry->d_sb; atomic_inc(&lower_sb->s_active); sdcardfs_set_lower_super(sb, lower_sb); /* inherit maxbytes from lower file system */ sb->s_maxbytes = lower_sb->s_maxbytes; /* * Our c/m/atime granularity is 1 ns because we may stack on file * systems whose granularity is as good. */ sb->s_time_gran = 1; sb->s_magic = SDCARDFS_SUPER_MAGIC; sb->s_op = &sdcardfs_sops; /* see comment next to the definition of sdcardfs_d_alloc_root */ sb->s_root = sdcardfs_d_alloc_root(sb); if (!sb->s_root) { err = -ENOMEM; goto out_sput; } /* link the upper and lower dentries */ sb->s_root->d_fsdata = NULL; err = new_dentry_private_data(sb->s_root); if (err) goto out_freeroot; /* set the lower dentries for s_root */ sdcardfs_set_lower_path(sb->s_root, &lower_path); /* call interpose to create the upper level inode */ err = sdcardfs_interpose(sb->s_root, sb, &lower_path); if (!err) { /* setup permission policy */ switch(sb_info->options.derive) { case DERIVE_NONE: setup_derived_state(sb->s_root->d_inode, PERM_ROOT, 0, AID_ROOT, AID_SDCARD_RW, 00775); sb_info->obbpath_s = NULL; break; case DERIVE_LEGACY: /* Legacy behavior used to support internal multiuser layout which * places user_id at the top directory level, with the actual roots * just below that. Shared OBB path is also at top level. */ setup_derived_state(sb->s_root->d_inode, PERM_LEGACY_PRE_ROOT, 0, AID_ROOT, AID_SDCARD_R, 00771); /* initialize the obbpath string and lookup the path * sb_info->obb_path will be deactivated by path_put * on sdcardfs_put_super */ sb_info->obbpath_s = kzalloc(PATH_MAX, GFP_KERNEL); snprintf(sb_info->obbpath_s, PATH_MAX, "%s/obb", dev_name); err = prepare_dir(sb_info->obbpath_s, sb_info->options.fs_low_uid, sb_info->options.fs_low_gid, 00755); if(err) printk(KERN_ERR "sdcardfs: %s: %d, error on creating %s\n", __func__,__LINE__, sb_info->obbpath_s); break; case DERIVE_UNIFIED: /* Unified multiuser layout which places secondary user_id under * /Android/user and shared OBB path under /Android/obb. */ setup_derived_state(sb->s_root->d_inode, PERM_ROOT, 0, AID_ROOT, AID_SDCARD_R, 00771); sb_info->obbpath_s = kzalloc(PATH_MAX, GFP_KERNEL); snprintf(sb_info->obbpath_s, PATH_MAX, "%s/Android/obb", dev_name); break; } fix_derived_permission(sb->s_root->d_inode); if (!silent) printk(KERN_INFO "sdcardfs: mounted on top of %s type %s\n", dev_name, lower_sb->s_type->name); goto out; } /* else error: fall through */ free_dentry_private_data(sb->s_root); out_freeroot: dput(sb->s_root); out_sput: /* drop refs we took earlier */ atomic_dec(&lower_sb->s_active); packagelist_destroy(sb_info->pkgl_id); out_freesbi: kfree(SDCARDFS_SB(sb)); sb->s_fs_info = NULL; out_free: path_put(&lower_path); out: return err; }
/* * our custom d_alloc_root work-alike * * we can't use d_alloc_root if we want to use our own interpose function * unchanged, so we simply call our own "fake" d_alloc_root */ static struct dentry *sdcardfs_d_alloc_root(struct super_block *sb) { struct dentry *ret = NULL; if (sb) { static const struct qstr name = { .name = "/", .len = 1 }; ret = d_alloc(NULL, &name); if (ret) { d_set_d_op(ret, &sdcardfs_ci_dops); ret->d_sb = sb; ret->d_parent = ret; } } return ret; } #endif DEFINE_MUTEX(sdcardfs_super_list_lock); LIST_HEAD(sdcardfs_super_list); EXPORT_SYMBOL_GPL(sdcardfs_super_list_lock); EXPORT_SYMBOL_GPL(sdcardfs_super_list); /* * There is no need to lock the sdcardfs_super_info's rwsem as there is no * way anyone can have a reference to the superblock at this point in time. */ static int sdcardfs_read_super(struct super_block *sb, const char *dev_name, void *raw_data, int silent) { int err = 0; int debug; struct super_block *lower_sb; struct path lower_path; struct sdcardfs_sb_info *sb_info; struct inode *inode; printk(KERN_INFO "sdcardfs version 2.0\n"); if (!dev_name) { printk(KERN_ERR "sdcardfs: read_super: missing dev_name argument\n"); err = -EINVAL; goto out; } printk(KERN_INFO "sdcardfs: dev_name -> %s\n", dev_name); printk(KERN_INFO "sdcardfs: options -> %s\n", (char *)raw_data); /* parse lower path */ err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &lower_path); if (err) { printk(KERN_ERR "sdcardfs: error accessing lower directory '%s'\n", dev_name); goto out; } /* allocate superblock private data */ sb->s_fs_info = kzalloc(sizeof(struct sdcardfs_sb_info), GFP_KERNEL); if (!SDCARDFS_SB(sb)) { printk(KERN_CRIT "sdcardfs: read_super: out of memory\n"); err = -ENOMEM; goto out_free; } sb_info = sb->s_fs_info; /* parse options */ err = parse_options(sb, raw_data, silent, &debug, &sb_info->options); if (err) { printk(KERN_ERR "sdcardfs: invalid options\n"); goto out_freesbi; } /* set the lower superblock field of upper superblock */ lower_sb = lower_path.dentry->d_sb; atomic_inc(&lower_sb->s_active); sdcardfs_set_lower_super(sb, lower_sb); /* inherit maxbytes from lower file system */ sb->s_maxbytes = lower_sb->s_maxbytes; /* * Our c/m/atime granularity is 1 ns because we may stack on file * systems whose granularity is as good. */ sb->s_time_gran = 1; sb->s_magic = SDCARDFS_SUPER_MAGIC; sb->s_op = &sdcardfs_sops; /* get a new inode and allocate our root dentry */ inode = sdcardfs_iget(sb, lower_path.dentry->d_inode, 0); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_sput; } sb->s_root = d_make_root(inode); if (!sb->s_root) { err = -ENOMEM; goto out_iput; } d_set_d_op(sb->s_root, &sdcardfs_ci_dops); /* link the upper and lower dentries */ sb->s_root->d_fsdata = NULL; err = new_dentry_private_data(sb->s_root); if (err) goto out_freeroot; /* set the lower dentries for s_root */ sdcardfs_set_lower_path(sb->s_root, &lower_path); /* * No need to call interpose because we already have a positive * dentry, which was instantiated by d_make_root. Just need to * d_rehash it. */ d_rehash(sb->s_root); /* setup permission policy */ sb_info->obbpath_s = kzalloc(PATH_MAX, GFP_KERNEL); mutex_lock(&sdcardfs_super_list_lock); if(sb_info->options.multiuser) { setup_derived_state(sb->s_root->d_inode, PERM_PRE_ROOT, sb_info->options.fs_user_id, AID_ROOT, false, sb->s_root->d_inode); snprintf(sb_info->obbpath_s, PATH_MAX, "%s/obb", dev_name); /*err = prepare_dir(sb_info->obbpath_s, sb_info->options.fs_low_uid, sb_info->options.fs_low_gid, 00755);*/ } else { setup_derived_state(sb->s_root->d_inode, PERM_ROOT, sb_info->options.fs_user_id, AID_ROOT, false, sb->s_root->d_inode); snprintf(sb_info->obbpath_s, PATH_MAX, "%s/Android/obb", dev_name); } fix_derived_permission(sb->s_root->d_inode); sb_info->sb = sb; list_add(&sb_info->list, &sdcardfs_super_list); mutex_unlock(&sdcardfs_super_list_lock); if (!silent) printk(KERN_INFO "sdcardfs: mounted on top of %s type %s\n", dev_name, lower_sb->s_type->name); goto out; /* all is well */ /* no longer needed: free_dentry_private_data(sb->s_root); */ out_freeroot: dput(sb->s_root); out_iput: iput(inode); out_sput: /* drop refs we took earlier */ atomic_dec(&lower_sb->s_active); out_freesbi: kfree(SDCARDFS_SB(sb)); sb->s_fs_info = NULL; out_free: path_put(&lower_path); out: return err; }
static struct dentry *unionfs_d_alloc_root(struct super_block *sb) { struct dentry *ret = NULL; if (sb) { static const struct qstr name = {.name = "/",.len = 1 }; ret = d_alloc(NULL, &name); if (ret) { ret->d_op = &unionfs_dops; ret->d_sb = sb; ret->d_parent = ret; } } return ret; } static int unionfs_read_super(struct super_block *sb, void *raw_data, int silent) { int err = 0; struct unionfs_dentry_info *hidden_root_info = NULL; int bindex, bstart, bend; unsigned long long maxbytes; print_entry_location(); if (!raw_data) { printk(KERN_WARNING "unionfs_read_super: missing data argument\n"); err = -EINVAL; goto out; } /* * Allocate superblock private data */ stopd_lhs(sb) = KZALLOC(sizeof(struct unionfs_sb_info), GFP_KERNEL); if (!stopd(sb)) { printk(KERN_WARNING "%s: out of memory\n", __FUNCTION__); err = -ENOMEM; goto out; } stopd(sb)->b_end = -1; atomic_set(&stopd(sb)->usi_generation, 1); init_rwsem(&stopd(sb)->usi_rwsem); hidden_root_info = unionfs_parse_options(sb, raw_data); if (IS_ERR(hidden_root_info)) { printk(KERN_WARNING "unionfs_read_super: error while parsing options (err = %ld)\n", PTR_ERR(hidden_root_info)); err = PTR_ERR(hidden_root_info); hidden_root_info = NULL; goto out_free; } if (hidden_root_info->udi_bstart == -1) { err = -ENOENT; goto out_free; } /* set the hidden superblock field of upper superblock */ bstart = hidden_root_info->udi_bstart; BUG_ON(bstart != 0); sbend(sb) = bend = hidden_root_info->udi_bend; for (bindex = bstart; bindex <= bend; bindex++) { struct dentry *d; d = hidden_root_info->udi_dentry[bindex]; set_stohs_index(sb, bindex, d->d_sb); } /* Unionfs: Max Bytes is the maximum bytes from among all the branches */ maxbytes = -1; for (bindex = bstart; bindex <= bend; bindex++) if (maxbytes < stohs_index(sb, bindex)->s_maxbytes) maxbytes = stohs_index(sb, bindex)->s_maxbytes; sb->s_maxbytes = maxbytes; sb->s_op = &unionfs_sops; sb->s_export_op = &unionfs_export_ops; /* * we can't use d_alloc_root if we want to use * our own interpose function unchanged, * so we simply call our own "fake" d_alloc_root */ sb->s_root = unionfs_d_alloc_root(sb); if (!sb->s_root) { err = -ENOMEM; goto out_dput; } /* link the upper and lower dentries */ dtopd_lhs(sb->s_root) = NULL; if ((err = new_dentry_private_data(sb->s_root))) goto out_freedpd; /* Set the hidden dentries for s_root */ for (bindex = bstart; bindex <= bend; bindex++) { struct dentry *d; d = hidden_root_info->udi_dentry[bindex]; set_dtohd_index(sb->s_root, bindex, d); } set_dbstart(sb->s_root, bstart); set_dbend(sb->s_root, bend); /* Set the generation number to one, since this is for the mount. */ atomic_set(&dtopd(sb->s_root)->udi_generation, 1); /* call interpose to create the upper level inode */ if ((err = unionfs_interpose(sb->s_root, sb, 0))) goto out_freedpd; unlock_dentry(sb->s_root); goto out; out_freedpd: if (dtopd(sb->s_root)) { KFREE(dtohd_ptr(sb->s_root)); free_dentry_private_data(dtopd(sb->s_root)); } DPUT(sb->s_root); out_dput: if (hidden_root_info && !IS_ERR(hidden_root_info)) { for (bindex = hidden_root_info->udi_bstart; bindex <= hidden_root_info->udi_bend; bindex++) { struct dentry *d; d = hidden_root_info->udi_dentry[bindex]; if (d) DPUT(d); if (stopd(sb) && stohiddenmnt_index(sb, bindex)) mntput(stohiddenmnt_index(sb, bindex)); } KFREE(hidden_root_info->udi_dentry); KFREE(hidden_root_info); hidden_root_info = NULL; } out_free: KFREE(stopd(sb)->usi_data); KFREE(stopd(sb)); stopd_lhs(sb) = NULL; out: if (hidden_root_info && !IS_ERR(hidden_root_info)) { KFREE(hidden_root_info->udi_dentry); KFREE(hidden_root_info); } print_exit_status(err); return err; }